Electronic systems and circuits have made a significant contribution towards the advancement of modern society and are utilized in a number of applications to achieve advantageous results. Numerous electronic technologies such as digital computers, calculators, audio devices, video equipment, and telephone systems have facilitated increased productivity and reduced costs in analyzing and communicating data, ideas and trends in most areas of business, science, education and entertainment. Frequently, electronic systems designed to provide these advantageous results are realized through the use of various functional electronic components included on printed circuit boards. While the printed circuit boards typically provide advantageous organization and configuration of the electronic components, there are often flexibility and/or extensibility limitations associated with printed circuit board configurations.
The importance of information processed and communicated by modern electronic systems is increasing and can result in significant economic impact if the processing and communication operations are not reliable. For example, an almost insatiable desire for increased communication bandwidth and information processing capacity has led to a tremendous demand for advanced capabilities. To obtain desired performance results from electronic components it is usually critical for the components to operate reliably. Without reliable operation an electronic component usually does not perform properly and results are suspect.
There are a number of things that can impact reliability. Actual in field conditions can have a significant impact on reliability and users typically expose electronic components to a wide variety of operating conditions. For example, a high temperature environmental condition also contributes to stressing the components in a detrimental manner and increases the likelihood of a failure. The number of “operations” electronic components perform (e.g., transistors turning on and off as data traffic passes through a communications component), the higher the likelihood of a failure typically because the operations usually electrically stress the components. As a component participates in greater operational activities and diverse environments, accurately maintaining components becomes more difficult.
Systems that include printed circuit boards are often large and complex systems and maintaining large systems is usually very complicated. Printed circuited boards are usually inserted in a card cage or chassis coupled to a back plane. In some implementations multiple “daughter” printed circuit boards can be coupled to a “mother board” that also operates as a back plane. The back plane is typically a passive “receptacle” for receiving multiple printed circuit boards and include busses for communicating information between the printed circuit boards. However, the number, the type and the configuration electronic components on printed circuit board coupled to a back plane can have a significant impact on maintenance.
Large printed circuit boards are often pose significant maintenance difficulties. Large circuit boards are bulky and usually difficult to handle and maneuver. In addition, maintenance of large printed circuit boards is usually very resource intensive. Electronic components usually have some probability of failure and the probability of any one of them failing typically increases as the number of components on a board increases. With increasingly sophisticated systems even one component failure can have significant detrimental impacts. Even with just one problem component a printed circuit board often has to be entirely replaced. Replacing a printed circuit board with a lot of components on it can be very costly.
Another traditional approach is to plug additional printed circuit boards into a back plane. However plugging additional printed circuit boards into a back plane occupies precious back plane space. Increasing the size of the back plane to accommodate additional boards consumes resources to build a larger back plane. In addition chassis with larger back planes are also typically larger, making the entire system bulkier, often less maneuverable and mobile. Larger backplanes also make cooling more difficult by tending to hinder airflow, thereby reducing reliability further by driving up operating temperatures. Larger chassis also usually occupy larger portions of precious floor space, such as in centralized processing facilities (e.g., a server farm).